/* CambiarCaldera — hoja de estilos única. Sin dependencias externas. */
:root{
  --bg:#fbfaf7; --fg:#1d2528; --muted:#5b676c; --card:#ffffff; --border:#e3e0d8;
  --brand:#0f6b63; --brand-ink:#ffffff; --brand-soft:#e2f1ee; --accent:#c25a12; --accent-soft:#fdeedd;
  --note:#e8f1fb; --note-b:#9cc0e8; --warn:#fff3d6; --warn-b:#e5b94a; --ok:#e3f4e6;
  --radius:12px; --maxw:1100px; --read:740px;
  --font:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --serif:Georgia,"Iowan Old Style","Times New Roman",serif;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#121819; --fg:#e8ecec; --muted:#9aa8ab; --card:#1a2224; --border:#2c3739;
    --brand:#3fb8aa; --brand-ink:#0b1514; --brand-soft:#173331; --accent:#f0a05a; --accent-soft:#33261a;
    --note:#16283a; --note-b:#2f5a85; --warn:#352d14; --warn-b:#8a6d1c; --ok:#17301c;
  }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);font-family:var(--font);line-height:1.65;font-size:17px}
img,svg{max-width:100%;height:auto}
a{color:var(--brand);text-underline-offset:2px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:4px}
.skip{position:absolute;left:-999px;top:0;background:var(--brand);color:var(--brand-ink);padding:.6rem 1rem;z-index:100}
.skip:focus{left:8px;top:8px}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* Cabecera */
.site-header{background:var(--card);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:50}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:64px}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.15rem;color:var(--fg);text-decoration:none;letter-spacing:-.01em}
.logo span em{color:var(--brand);font-style:normal}
.logo svg{width:30px;height:30px;flex:none}
.nav ul{list-style:none;margin:0;padding:0;display:flex;gap:4px;flex-wrap:wrap}
.nav a{display:block;padding:.45rem .75rem;border-radius:8px;color:var(--fg);text-decoration:none;font-size:.95rem;font-weight:500}
.nav a:hover,.nav a[aria-current="page"]{background:var(--brand-soft);color:var(--brand)}
.nav-toggle{display:none;background:none;border:1px solid var(--border);border-radius:8px;padding:.45rem .7rem;color:var(--fg);font:inherit;cursor:pointer}
@media (max-width:860px){
  .nav-toggle{display:block}
  .nav{display:none;position:absolute;left:0;right:0;top:64px;background:var(--card);border-bottom:1px solid var(--border);padding:8px 20px 14px}
  .nav.open{display:block}
  .nav ul{flex-direction:column}
}

/* Tipografía */
h1,h2,h3{line-height:1.2;letter-spacing:-.015em;margin:0 0 .6em}
h1{font-size:clamp(1.9rem,4.2vw,2.7rem);font-weight:800}
h2{font-size:1.55rem;margin-top:2.2em;font-weight:750;scroll-margin-top:80px}
h3{font-size:1.18rem;margin-top:1.6em;font-weight:700}
p,ul,ol{margin:0 0 1.1em}
.lead{font-size:1.2rem;color:var(--muted)}
.meta{color:var(--muted);font-size:.9rem;display:flex;flex-wrap:wrap;gap:6px 16px;margin-bottom:1.4rem}
.crumbs{font-size:.88rem;color:var(--muted);margin:22px 0 10px}
.crumbs a{color:var(--muted)}
.crumbs span[aria-hidden]{margin:0 6px}

/* Hero */
.hero{padding:56px 0 40px;background:linear-gradient(180deg,var(--brand-soft),transparent)}
.hero .wrap{display:grid;grid-template-columns:1.25fr .75fr;gap:40px;align-items:center}
.hero p.lead{max-width:56ch}
.btns{display:flex;flex-wrap:wrap;gap:12px;margin-top:22px}
.btn{display:inline-block;padding:.8rem 1.25rem;border-radius:10px;background:var(--brand);color:var(--brand-ink);font-weight:700;text-decoration:none;border:2px solid var(--brand)}
.btn:hover{filter:brightness(1.08)}
.btn.ghost{background:transparent;color:var(--brand)}
.hero-card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:22px;box-shadow:0 8px 28px rgba(0,0,0,.06)}
.hero-card h2{font-size:1.05rem;margin:0 0 .8em;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}
.stat{display:flex;justify-content:space-between;gap:12px;padding:10px 0;border-bottom:1px dashed var(--border)}
.stat:last-child{border:0}
.stat b{font-size:1.15rem;color:var(--brand);white-space:nowrap}
.stat small{display:block;color:var(--muted)}
@media (max-width:820px){.hero .wrap{grid-template-columns:1fr}}

/* Rejillas y tarjetas */
section.block{padding:44px 0}
section.block.alt{background:var(--card);border-block:1px solid var(--border)}
.section-head{max-width:var(--read);margin-bottom:26px}
.section-head h2{margin-top:0}
.grid{display:grid;gap:18px;grid-template-columns:repeat(auto-fill,minmax(270px,1fr))}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:20px;display:flex;flex-direction:column;gap:8px;text-decoration:none;color:var(--fg);transition:transform .15s,box-shadow .15s}
a.card:hover{transform:translateY(-2px);box-shadow:0 8px 22px rgba(0,0,0,.08)}
.card .tag{font-size:.78rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--accent)}
.card h3{margin:0;font-size:1.15rem}
.card p{margin:0;color:var(--muted);font-size:.96rem}
.card .more{margin-top:auto;color:var(--brand);font-weight:650;font-size:.95rem}
.steps{counter-reset:s;list-style:none;padding:0;display:grid;gap:16px;grid-template-columns:repeat(auto-fit,minmax(230px,1fr))}
.steps li{counter-increment:s;background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:18px 18px 18px 64px;position:relative}
.steps li::before{content:counter(s);position:absolute;left:16px;top:16px;width:34px;height:34px;border-radius:50%;background:var(--brand);color:var(--brand-ink);display:grid;place-items:center;font-weight:800}
.steps li b{display:block;margin-bottom:2px}

/* Artículo */
.article-layout{display:grid;grid-template-columns:minmax(0,var(--read)) 280px;gap:48px;justify-content:center;padding-bottom:50px}
.article h1{margin-bottom:.4em}
.article h2{border-top:1px solid var(--border);padding-top:1.1em}
.article h2:first-of-type{border-top:0;padding-top:0}
.article ul,.article ol{padding-left:1.3em}
.article li{margin-bottom:.4em}
.article blockquote{margin:1.4em 0;padding:.2em 1.2em;border-left:4px solid var(--brand);color:var(--muted)}
.toc{position:sticky;top:84px;align-self:start;background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:16px 18px;font-size:.92rem}
.toc b{display:block;margin-bottom:8px;text-transform:uppercase;letter-spacing:.06em;font-size:.78rem;color:var(--muted)}
.toc ol{margin:0;padding-left:1.1em}
.toc li{margin-bottom:.45em}
.toc a{text-decoration:none;color:var(--fg)}
.toc a:hover{color:var(--brand);text-decoration:underline}
@media (max-width:980px){.article-layout{grid-template-columns:1fr}.toc{position:static;order:-1}}
.callout{border:1px solid var(--note-b);background:var(--note);border-radius:var(--radius);padding:14px 18px;margin:1.4em 0}
.callout.warn{border-color:var(--warn-b);background:var(--warn)}
.callout.ok{border-color:#7cbf88;background:var(--ok)}
.callout p:last-child{margin:0}
.callout strong:first-child{display:block;margin-bottom:2px}
.tablewrap{overflow-x:auto;margin:1.3em 0;border:1px solid var(--border);border-radius:var(--radius);background:var(--card)}
table{border-collapse:collapse;width:100%;font-size:.95rem;min-width:480px}
th,td{padding:.7rem .9rem;text-align:left;border-bottom:1px solid var(--border);vertical-align:top}
th{background:var(--brand-soft);font-weight:700}
tr:last-child td{border-bottom:0}
caption{caption-side:bottom;padding:.6rem .9rem;color:var(--muted);font-size:.85rem;text-align:left}
details{border:1px solid var(--border);border-radius:10px;background:var(--card);padding:.2rem 1rem;margin-bottom:10px}
summary{cursor:pointer;font-weight:650;padding:.7rem 0}
details[open] summary{border-bottom:1px solid var(--border);margin-bottom:.7rem}
.sources{font-size:.9rem;color:var(--muted);border-top:1px solid var(--border);margin-top:2.4em;padding-top:1em}
.sources ul{padding-left:1.2em}
.related{margin-top:2.4em}
.author-box{margin-top:2.4em;padding:16px 20px;background:var(--brand-soft);border-radius:var(--radius);border:1px solid var(--border)}
.author-box b{display:block;margin-bottom:4px}
.author-box p{margin:0 0 .5em;font-size:.95rem}
.author-box p:last-child{margin:0;font-size:.88rem}
.article li small{color:var(--muted)}
.cat-intro{max-width:var(--read)}

/* Calculadora */
.calc{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:22px;margin:1.4em 0}
.calc form{display:grid;gap:16px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.field label{display:block;font-weight:650;margin-bottom:4px;font-size:.95rem}
.field input{width:100%;padding:.65rem .75rem;border:1px solid var(--border);border-radius:8px;background:var(--bg);color:var(--fg);font:inherit}
.field small{display:block;color:var(--muted);font-size:.82rem;margin-top:3px}
.results{margin-top:22px;display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}
.res{background:var(--brand-soft);border-radius:10px;padding:14px 16px}
.res small{display:block;color:var(--muted);font-size:.82rem}
.res b{font-size:1.5rem;color:var(--brand);display:block;line-height:1.2}
.res.bad b{color:var(--accent)}
#calc-msg{margin-top:14px;font-weight:600}

/* Publicidad (solo se renderiza si activas AdSense al construir) */
.ad-slot{margin:2rem 0;text-align:center;min-height:90px}
.ad-label{display:block;font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:4px}

/* Pie */
.site-footer{margin-top:40px;background:var(--card);border-top:1px solid var(--border);padding:38px 0 26px;font-size:.93rem;color:var(--muted)}
.foot-grid{display:grid;gap:28px;grid-template-columns:1.4fr 1fr 1fr}
.site-footer h2{font-size:.82rem;text-transform:uppercase;letter-spacing:.08em;margin:0 0 .8em;color:var(--fg)}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin-bottom:.4em}
.site-footer a{color:var(--muted)}
.site-footer a:hover{color:var(--brand)}
.disclaimer{border-top:1px solid var(--border);margin-top:26px;padding-top:16px;font-size:.84rem}
@media (max-width:760px){.foot-grid{grid-template-columns:1fr}}
@media print{.site-header,.site-footer,.toc,.ad-slot,.nav-toggle{display:none}body{background:#fff;color:#000}}